It's not unusual for a blockbuster film to go through several different iterations of itself before it finally settles on the version that will make it up on the big screen. Sometimes the cuts can be detrimental like with Suicide Squad, or you can get something like Rogue One: a film that was less obviously restructured and doesn't impact the quality. You only need to watch one of the trailers to see that a lot ended up not making it into the theatrical cut, and now thanks to a Q & A with some of the concept artists and costume designers, we now some other tidbits that didn't make it as well.
A special Q&A event was held at the London comic book store Gosh, and in attendance were several of the concept artist and costume designers who worked on Rogue One: A Star Wars Story. Thanks to the Hyperdrive Tumblr account, we know some of the major talking points the Q&A went over. Most of the designers all have a history with Star Wars, having worked on Star Wars: The Force Awakens and Star Wars: The Last Jedi (most of them are aksi working on the untitled Han Solo project too). They also confirmed what we mostly already knew: a lot of material for the film that was shot went unused.
One of the bigger things to drop was that Saw Gerrera was originally supposed to appear on a different planet than Jedha, and that there were designs for an ice planet and a second jungle world. What would have happened on these new planets is irrelevant, but I wouldn't count out seeing them in the future. Nothing is ever really thrown away when it comes to this franchise.
The Q&A is filled with fun little factoids about the logistics of design, and other such trivia. For instance, there are no 45-degree angles in Star Wars for some reason. It also took them two months to design the tower on Scarif (where Jyn and crew break into to steal the Death Star plans) but then the design was scrapped and they made a new one in two hours. Baze Malbus was also one of the rare characters to go through no design changes after he was initially conceived.
Director Gareth Edwards worked closely with the concept artists to get the right designs for all the characters, and that even background characters designs were treated just as important as the main characters. In a sci-fi movie as densely packed with unique imagery as Star Wars, design must not be easy, but they credited the work of Ralph McQuarrie and Joe Johnston as sources of inspiration.
Clearly, Rogue One went through a lot of different iterations, and we can only hope that we get to see some of this extra footage released in some way. I'd be very interested to see how the film was originally supposed to end.